[DIYengineerParticipant]

Take a peek:

http://www.youtube.com/watch?v=sCJ8pBcreAk

The other run smooth, not choppy and don’t bounce all over.

Any clues?

Connections are fine, swapped another stepper and same results.

I was using Mach 3 to Jog them.

305oz steppers connected to 4 axis hobby cnc pro board.

[SchweppesParticipant]

I would guess that it’s faulty straight out of the box…generally when a motor bounces around like that, it’s because something isn’t balanced right.

I’m not sure if I read right, but does this happen solely if something is on the x axis? or is it just that single motor doing it regardless of what axis it’s hooked up to? if it’s the former, it something you’ve got coded up right, latter..definitely broke out of the box.

Or I’m completely wrong, who knows.

[ChrisKeymaster]

@DIYengineer — first off, congrats! Looks like you’re making some great progress.

It might be a little hasty to assume the motor’s broken without troubleshooting a bit first. The easiest thing to do would be to switch the motors, for example swap the Z motor with the X motor. If you still get the same behavior, you’ll know it’s something in the driver board/software.

I remember seeing some behavior like that when our scaling settings were off in our control software (in our case EMC2).

I would double-check all the wiring with a multi-meter for connectivity and also to make sure the correct wires go to the correct pins on the board.

Also double-check your jumpers for X; if they’re set differently than what your telling the software, that will affect the scaling and cause a problem like that seen in the video.

[DIYengineerParticipant]

I swapped 2 other steppers in and they all did the same thing which takes the steppers out of the equation. I was using 1/4 stepping (Jumpers J2 and J3 installed on X,Y,Z axis). J4 Un-installed on all (X,Y,Z). Triple checked wiring, triple checked the pin out software inputs for mach 3 to make sure that they were correct. All the settings were correct. Ripping the board out and going through the X axis section and re-flow all the joints just in case one is barely connected. I posted on the hobbycnc help forum as well with no reply yet.

I will reflow and get back to everyone.

[TaylorKeymaster]

My money is on the software settings. Been a while since I worked with Mach3, so these are all guesses. Look at scaling, look at jog speed and acceleration. Pull everything back to see if you can’t find a ballpark where things smooth out. Also, does the spindle on the wonky axis turn back and forth, like it can’t decide which direction it wants to go? Can you easily cause it to stop moving all together by gripping it with your fingers? These tests should help narrow things down.

Also, try changing jumper settings on the axis in question. Does the motor behave differently? If so, how?

[DIYengineerParticipant]

REflowed all the solder joints on the board, 99% of them were already perfect although i did find a few here and there that took a bit more solder. Going to set the VREF on the 4th axis and setup 4th stepper just to make sure all is well with that axis since i’m checking the entire board, and mach 3 easily allows you to jog a 4th axis why not? haha..

On a better not I Picked up a Gateway 500SE tower from a friend (FREE) :), Made in 2002 1.8ghz Pentium 4, 512mb ddr ram, 64mb on board Intel video, 40gig ide HD, on board lan, and on board parallel. Runs windows XP pro 32 bit like a charm and passed the Mach 3 parallel port checker with very low latency! SO I have that tethered to my hobby CNC controller box. I think i’m going to gut my controller box and mount everything in the Gateway tower to save space and so all my wires are basically going to the same place.

Time to hook the board back up and see if the stepper issue went away (*Crosses fingers*).

[DIYengineerParticipant]

Well the main settings are:

Steps per INCH: 2000 (default)

Velocity inches: 120

Acceleration: 4inches

G’s: .010360

Step pulse:0

Dir Pulse:0

Those are basically the current settings by default, see anything that i should change?

[DIYengineerParticipant]

I reassembled the board and driver box, including the forth axis. The X axis problem vanished. A,X,Y axis are as SUPER SMOOTH. Z axis now has the case of the jitters, just not as bad as the original! I’m starting too think its just the little clamping mechanism doesn’t like 2 wires going into one port. Its a 8 wire stepper====>6 wire port. The communication wires are just twisted together in pairs and shoved in. When the machine is fully assembled as per the directions you solder the wire that was given to you with the kit and only 1 wire enters the clamping post.

also Inserted jumper J4 to override the voltage reduction in each axis, as well as running 1/2 step (Jumper J1 in each axis). Heat sinks get HOT HOT HOT without the current reduction on, but i wanted to take that out of the equation.

[TaylorKeymaster]

I’m sure you know this already, but I’d approach things one by one. First, drop some setting like steps/inch to 25% and see what effect it has. Bump it gradually back towards the default and note any changes. Is the problem identical? Or does the problem get better or worse? You can play with the jog speed in the same way.

Numbers will differ depending on your setup, so we don’t have a magic setting to give you. Your motor motion looks just like problems we had along the way – I’d be surprised if a faulty motor is to blame.

Are the settings applied identically to all three axes? Or can you change each axis individually?

[DIYengineerParticipant]

The settings are the same for all 4 axis’s, but can be adjusted individually. This is a 1.8 degree motor correct? So 200 Steps per 1 full revolution. The motors are not connected to the gantry or drive system yet so i have no clue what that number should be. 200x_____=steps per inch. Velocity and acceleration also no clue, is there a spec sheet for these steppers?

[DIYengineerParticipant]

I’m thinking the wires entering the clamping post are to blame… I will re-clamp and see what happens.

[DIYengineerParticipant]

going to re-flow the Z channel solder and see if the problem goes away like X channel did. Swapping steppers, and re attaching wires didn’t do anything. Its most likely a weak solder point.

Hopefully will have this figured out tonight so i can put up a new video of all 4 of them moving simultaneously while doing a gcode test run in mach 3. =P

[DIYengineerParticipant]

Test

[DIYengineerParticipant]

Test 2

[DIYengineerParticipant]

Ok sorry for the post before the picture, i wasn’t quite sure which format would work.

I re-soldered the Z axis section. Now it works fine only at full speed, but is jittery on the initial startup and slowdown which is still a big problem. Most likely going to have to re-flow the Z axis AGAIN, i cant believe its giving me this much trouble.

As for the picture above, those are basically the main settings i need. I guess the steps per inch should all rely on the ACME rod i purchased correct? Currently Using half steps as well (J1 Jumper installed, and disabled voltage reduction J4 on all axis)

[Author]

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